The subject matter of this disclosure relates generally to rotary equipment, and in particular to diagnostic techniques for rotary equipment components. Specifically, the invention concerns a pressure-based diagnostic for monitoring wear on components that operate on a fluid.
Pressure sensors provide utility across a wide range of industrial applications, including bulk fluid storage and transport, agriculture, environmental control, water and air distribution, food and beverage preparation, chemical and pharmaceutical production, and a range of manufacturing processes utilizing thermoplastics, glues, resins and other fluidic materials. Pressure measurements are also important to energy production and other hydrocarbon fuel applications, which involve a wide range of fluidic flows including natural gas, diesel, pulverized coal, water and steam.
Pressure sensing technologies range from simple spring gauges, strain gauges and other mechanical devices to advanced capacitive, piezoresistive and electrochemical sensors. In industrial systems, these are typically housed in a transmitter or other more generalized field device, which protects the sensor hardware and adds higher-order functionality such as signal processing and communications.
The most appropriate pressure measurement methods depend upon the properties of the process material and the demands of each particular processing application. In custody transfer, for example, differential pressure measurements are typically utilized to achieve flow sensitivity via Bernoulli's principle and other velocity-dependent effects. In energy production, gage and absolute pressure measurements are required to provide precision control of large-scale rotary equipment such as blowers, fans, compressors and turbines.
In rotary equipment applications, components that operate on the fluid are often susceptible to wear and tear due to interactions with the flow stream. Wear and tear occurs both gradually, due to blade and vane erosion, and discretely, due to debris impacts and other damage including the loss of a blade or vane, or of individual components such as tips, airfoil sections and thermal coatings.
In order to diagnose these forms of wear and tear, it is necessary to continuously monitor the operational condition of rotary equipment. Dedicated devices such as blade tip sensors and inlet debris sensors are expensive, however, and do not provide measurement functionality outside their particular diagnostic purpose. There is thus a need for diagnostic techniques that combine sensitivity to wear and tear with existing process measurements, and which are applicable across a range of custody transfer, power production, environmental control and other fluid flow applications.